I want to use a view throughout multiple viewcontrollers in a storyboard. Thus, I thought about designing the view in an external xib so changes are reflected in every viewcontroller. But how can one load a view from a external xib in a storyboard and is it even possible? If thats not the case, what other alternatives are availble to suit the situation abouve?

Isn't it that loadNibNamed calls init(coder:)? I have a crash trying to adapt your approach.
– FishmanNov 14 '16 at 9:15

@Fishman, if you try to load the view programmatically (rather than from the storyboard), it will crash because it doesn't currently have an init(frame:). See this tutorial for more details.
– SuragchJan 6 '17 at 8:18

6

Another common cause of crashing is not setting the custom view to the file's owner. See the red circle in my answer.
– SuragchJan 6 '17 at 8:22

4

Yeah I had set the class of the root view instead of the file owner and it was causing an infinite loop.
– devios1Feb 24 '17 at 0:31

For a while Christopher Swasey's approach was the best approach I had found. I asked a couple of the senior devs on my team about it and one of them had the perfect solution! It satisfies every one of the concerns that Christopher Swasey so eloquently addressed and it doesn't require boilerplate subclass code(my main concern with his approach). There is one gotcha, but other than that it is fairly intuitive and easy to implement.

Create a custom UIView class in a .swift file to control your xib. i.e. MyCustomClass.swift

Create a .xib file and style it as you want. i.e. MyCustomClass.xib

Set the File's Owner of the .xib file to be your custom class (MyCustomClass)

GOTCHA: leave the class value (under the identity Inspector) for your custom view in the .xib file blank. So your custom view will have no specified class, but it will have a specified File's Owner.

Hook up your outlets as you normally would using the Assistant Editor.

NOTE: If you look at the Connections Inspector you will notice that your Referencing Outlets do not reference your custom class (i.e. MyCustomClass), but rather reference File's Owner. Since File's Owner is specified to be your custom class, the outlets will hook up and work propery.

Make sure your custom class has @IBDesignable before the class statement.

NOTE: If you miss the Gotcha and set the class value inside your .xib file to be your custom class, then it will not draw in the storyboard and you will get a EXC_BAD_ACCESS error when you run the app because it gets stuck in an infinite loop of trying to initialize the class from the nib using the init?(coder aDecoder: NSCoder) method which then calls Self.nib.instantiate and calls the init again.

3) Wherever you want to use it in your storyboard, add a UIView as you normally would, select the newly added view, go to the Identity Inspector (the third icon on the upper right that looks like a rectangle with lines in it), and enter your subclass's name in as the "Class" under "Custom Class".

xibView.frame = self.frame; should be xibView.frame = CGRectMake(0, 0, self.frame.size.width, self.frame.size.height);, otherwise xibView will have an offset when the view is added to storyboard.
– BabyPandaMar 1 '16 at 13:09

late to the party but it seems he changed it to xibView.frame = self.bounds, which is a frame without offset
– Heavy_BulletsDec 21 '16 at 13:07

20

Results in a crash due to infinite recursion. Loading the nib creates another instance of the subclass.
– DavidMar 5 '17 at 20:59

2

The xib view's class should not be the same as this new subclass. If the xib is MyClass, you can make this new class MyClassContainer.
– user1021430May 26 '17 at 17:57

I've always found the "add it as a subview" solution unsatisfactory, seeing as it screws with (1) autolayout, (2) @IBInspectable, and (3) outlets. Instead, let me introduce you to the magic of awakeAfter:, an NSObject method.

awakeAfter lets you swap out the object actually woken up from a NIB/Storyboard with a different object entirely. That object is then put through the hydration process, has awakeFromNib called on it, is added as a view, etc.

We can use this in a "cardboard cut-out" subclass of our view, the only purpose of which will be to load the view from the NIB and return it for use in the Storyboard. The embeddable subclass is then specified in the Storyboard view's identity inspector, rather than the original class. It doesn't actually have to be a subclass in order for this to work, but making it a subclass is what allows IB to see any IBInspectable/IBOutlet properties.

This extra boilerplate might seem suboptimal—and in a sense it is, because ideally UIStoryboard would handle this seamlessly—but it has the advantage of leaving the original NIB and UIView subclass completely unmodified. The role it plays is basically that of an adapter or bridge class, and is perfectly valid, design-wise, as an additional class, even if it is regrettable. On the flip side, if you prefer to be parsimonious with your classes, @BenPatch's solution works by implementing a protocol with some other minor changes. The question of which solution is better boils down to a matter of programmer style: whether one prefers object composition or multiple inheritance.

Note: the class set on the view in the NIB file remains the same. The embeddable subclass is only used in the storyboard. The subclass can't be used to instantiate the view in code, so it shouldn't have any additional logic, itself. It should only contain the awakeAfter hook.

⚠️ The one significant drawback here is that if you define width, height, or aspect ratio constraints in the storyboard that don't relate to another view then they have to be copied over manually. Constraints that relate two views are installed on the nearest common ancestor, and views are woken from the storyboard from the inside-out, so by the time those constraints are hydrated on the superview the swap has already occurred. Constraints that only involve the view in question are installed directly on that view, and thus get tossed when the swap occurs unless they are copied.

Note that what is happening here is constraints installed on the view in the storyboard are copied to the newly instantiated view, which may already have constraints of its own, defined in its nib file. Those are unaffected.

instantiateViewFromNib is a type-safe extension to UIView. All it does is loop through the NIB's objects until it finds one that matches the type. Note that the generic type is the return value, so the type has to be specified at the call site.

That is mindboggling. If I'm not mistaken though, this only works "on the storyboard" - if you try to create such a class in code at runtime, I don't think it works. I believe.
– FattieJan 14 '17 at 14:30

The subclass should work in code just as well as the original class for all intents and purposes. If you want to load the view from a nib in code you would just instantiate it directly using the same technique. All the subclass does is take the code to instantiate the view from a nib and put it in a hook for the storyboard to use.
– Christopher SwaseyJan 16 '17 at 17:31

Actually I was wrong—it would work just as well if you could instantiate it, but you can't, because the view in the NIB will have the superclass as its type so instantiateViewFromNib won't return anything. Not a big deal either way IMO, the subclass is just a contrivance to hook into the storyboard, all the code should be on the original class.
– Christopher SwaseyJan 18 '17 at 19:07

1

Great! One thing tripped me up because I have little experience with xibs (I only ever worked with storyboards & programmatic approaches), leaving this here in case it helps someone: in the .xib file, you need to select the top level view, and set its class type to MyCustomView. In my xib the left inner-sidebar was missing by default; to turn it on, there's a button next to the "View as: iPhone 7" traits control near the bottom/left side.
– xaphodMar 23 '17 at 23:50

5

It brakes constraints when it replaced by another object. :(
– invoodooMay 5 '17 at 22:42

Best solution currently is to just use a custom view controller with its view defined in a xib, and simply delete the "view" property that Xcode creates inside the storyboard when adding the view controller to it (don't forget to set the name of the custom class though).

This will make the runtime automatically look for the xib and load it. You can use this trick for any kind of container views, or content view.

I think about alternative for using XIB views to be using View Controllerin separate storyboard.

Then in main storyboard in place of custom view use container view with Embed Segue and have StoryboardReference to this custom view controller which view should be placed inside other view in main storyboard.

Then we can set up delegation and communication between this embed ViewController and main view controller through prepare for segue. This approach is different then displaying UIView, but much simpler and more efficiently (from programming perspective) can be utilised to achieve the same goal, i.e. have reusable custom view that is visible in main storyboard

The additional advantage is that you can implement you logic in CustomViewController class and there set up all delegation and view preparation without creating separate (harder to find in project) controller classes, and without placing boilerplate code in main UIViewController using Component. I think this is good for reusable components ex. Music Player component (widget like) that is embeddable in other views.

Although the top most popular answers works fine, they are wrong. They all use File's owner as connection between class's outlets and UI components. File's owner is supposed to be used only for top-level objects not UIViews. Check out Apple developer document.
Having UIView as File's owner leads to these undesirable consequences.

You are forced to use the contentView. You are supposed to use self. It’s not only ugly, but also structurally wrong because data structure better convey it’s UI structure. Using contentView is like the opposite of declarative UI.

You can only have one UIView per Xib. An Xib is supposed to have multiple UIViews.

There's elegant way to do it without using File's owner. Please check this blog post. It explains how to do it the right way.

This solution can be used even if your class does not have the same name as the XIB.
For example, if you have a base view controller class controllerA which has a XIB name controllerA.xib and you subclassed this with controllerB and want to create an instance of controllerB in a storyboard, then you can:

create the view controller in the storyboard

set the class of the controller to the controllerB

delete the view of the controllerB in the storyboard

override load view in controllerA to:

*

- (void) loadView
{
//according to the documentation, if a nibName was passed in initWithNibName or
//this controller was created from a storyboard (and the controller has a view), then nibname will be set
//else it will be nil
if (self.nibName)
{
//a nib was specified, respect that
[super loadView];
}
else
{
//if no nib name, first try a nib which would have the same name as the class
//if that fails, force to load from the base class nib
//this is convenient for including a subclass of this controller
//in a storyboard
NSString *className = NSStringFromClass([self class]);
NSString *pathToNIB = [[NSBundle bundleForClass:[self class]] pathForResource: className ofType:@"nib"];
UINib *nib ;
if (pathToNIB)
{
nib = [UINib nibWithNibName: className bundle: [NSBundle bundleForClass:[self class]]];
}
else
{
//force to load from nib so that all subclass will have the correct xib
//this is convenient for including a subclass
//in a storyboard
nib = [UINib nibWithNibName: @"baseControllerXIB" bundle:[NSBundle bundleForClass:[self class]]];
}
self.view = [[nib instantiateWithOwner:self options:nil] objectAtIndex:0];
}
}

Here's the answer you've wanted all along. You can just create your CustomView class, have the master instance of it in a xib with all the subviews and outlets. Then you can apply that class to any instances in your storyboards or other xibs.

No need to fiddle with File's Owner, or connect outlets to a proxy or modify the xib in a peculiar way, or add an instance of your custom view as a subview of itself.

Just do this:

Import BFWControls framework

Change your superclass from UIView to NibView (or from UITableViewCell to NibTableViewCell)

That's it!

It even works with IBDesignable to refer your custom view (including the subviews from the xib) at design time in the storyboard.